Purchasing the Wind Tunnel Fan

Dear Fellow Basement Scientists,

I hope you all are pursuing your interests and attempting to satisfy your curiosity. With many other good things, it is fun and rewarding, but can take hard work. Alright, in our wind tunnel project our next piece of construction takes us to the diffuser! Recall our general wind tunnel design (in blue), appropriately drawn on the back on an envelope, You can see the diffuser on the right of the test section, it is long and expands to larger than the fan, in order to house it: